The notion of \((s,\delta , c)\) -potential function we have above, is a generalisation of the
so-called “\((\alpha ,c)\) -potential function" that was introduced in [1]}. Note that
the notion of \((\alpha ,c)\) -potential function implies the use of the \(\ell _1\) -norm in the analysis.
The setting we consider here is more general. The condition in (REF ),
somehow, implies that we are using the \(\ell _{r}\) -norm in our analysis, where \(r\)  is the Hölder conjugate of the
parameter \(s\)  in the \((s,\delta , c)\) -potential functionThat is, \(r\)  satisfies that \(r^{-1}+s^{-1}=1\) ..
